private void btnClear_Click(object sender, EventArgs e)
 {
     try
     {
         btnGenerar1Mas.Enabled = false;
         txtC.Text  = "";
         txtG.Text  = "";
         txtK.Text  = "";
         txtXo.Text = "";
         txtNumerosAGenerar.Text = "20";
         dgvNumeros.Rows.Clear();
         txtXo.Focus();
     }
     catch
     {
         IOException ex = new IOException();
         ex.otroError();
     }
 }